Method and apparatus for interrupting liquid coating



March 22, 1966 J. H. BROWN 3,

METHOD AND APPARATUS FOR INTERRUPTING LIQUID COATING Filed Oct. 31, 19622 Sheets-Sheet 1 Q W M MIN QOIN- 42 a5 66 62 E "IE IIIT' IIIIIi[IEIEEI'EIEIEIEIEIEEIEIEIEEIEIEIII EIEII 40 F glen IN V EN TOR. 7"JACK H. BROWN A TT RNEY.

2 Sheets-$heet 2 J. H. BROWN {I mm March 22, 1966 METHOD AND APPARATUSFOR INTERRUPTING LIQUID COATING Filed Oct. 51, 1962 IN VEN TOR. .JACK H.BROWN United States Patent 3,242,003 METHOD AND APPARATUS FORINTERRUPTING LIQUID COATING Jack Heywood Brown, Beverly, Mass., assignorto Swift & Company, Chicago, 111., a corporation of Illinois Filed Oct.31, 1962, Ser. No. 234,448 5 Claims. (Cl. 117-105.3)

The present invention deals generally with improvements in method andapparatus for coating articles by pouring liquid material thereon. Morespecifically, this invention deals with an improved method and apparatusfor interrupting the descent of liquid from a liquid pouring device.

A well-known method and means for applying a coating of liquid materialuniformly to the surface of an article involves the pouring of a thincurtain of such liquid across the path along which the article ispassed. Various liquid finishing materials, such as dyes, lacquers,varnish, and the like, may be applied to sheet-like items in thismanner. Usually, the liquid material is poured in a curtain disposedgenerally transversely of the direction of motion of the article to becoated. The liquid descends by gravity from a weir or orifice typereservoir across the path of the article, and the excess is recovered ina pan or sump and usually recirculated to the reservoir. In mostinstances, the curtain is poured continuously as successive articles arepassed therethrough. Excess liquid falling between articles is recoveredin the pan and there is little loss. However, where such articles areautomatically fed through the curtain of liquid, a system of conveyors,detouring around the pan is utilized and the article must span,unsupported, a narrow space extending to either side of the curtain ofliquid. Such apparatus is shown in the Glaus Patents Nos. 2,935,424 and2,963,002.

Such systems present no difliculty where the articles to be coated arerigid. However, where flexible material such as leather, textiles, andother sheet-like material is to be coated by pouring, some special meansmust be provided to enable the material to bridge the gap across theliquid pan. Otherwise, the weight of the material, or the weight of theliquid falling thereon, may cause it to fall into the pan.

In the past where such flexible articles have been supported on aconveyor device while passing through the curtain of liquid severalproblems have resulted. Portions of the device exposed betweensuccessive articles have been coated by the liquid material and haverequired extensive cleaning. Furthermore, the liquid falling on theconveyor device has been lost; and often such material is transferred tothe underside of successive articles in an undesirable manner.

Accordingly, it is an object of the present invention to provide animproved method and apparatus for briefly interrupting a descendingcurtain of liquid material at desired times.

A further object of the present invention is to provide an improvedmethod and apparatus for coating particles by pouring liquid thereonwherein the curtain of liquid may be briefly interrupted while anexposed portion of a conveyor device passes underneath.

Basically, this invention contemplates the substantially continuouspouring of a curtain of liquid material through which articles are to bepassed and, as a conveying means passes therebeneath, exposed betweensuccessive articles, briefly interrupting the curtain of liquid byconcurrently passing a filament through the length thereof.

An apparatus devised for carrying out this method comprises, incombination with a pouring means and an article conveying means, asingle filament member held parallel to the curtain of liquid at a levelbetween the pour- 3,242,003 Patented Mar. 22, 1966 ing and conveyingmeans, and means connected to the filament to reciprocate it through thecurtain of liquid.

Additional objects and advantages of the present invention will becomeapparent upon reading the following specification in conjunction withthe drawings wherein:

FIGURE 1 is a side elevation of the apparatus of this invention with adevice for carrying an article to be coated partially shown;

FIGURE 2 is a plan view of the apparatus of FIGURE 1 with parts brokenaway;

FIGURE 3 is a front elevation of the apparatus of FIG- URE 1.

In practicing the present invention, an article to be coated is placedupon a conveyor member which is constrained to travel in a given path. Aliquid material, to be applied to the article, is continuously poured ina descending curtain disposed generally transversely of the path at alocation to intercept the article. As the leading edge of the conveyormember approaches the curtain of liquid the latter is interruptedbriefly to form a horizontal space in the curtain through which theleading edge of the conveyor member may pass without being coated.

The curtain of liquid may be best interrupted along a line close to itsorigin or source of liquid material. This is done by passing a singlefilament, such as piano wire held horizontal and parallel to the curtainof liquid quickly through the entire length of the liquid curtain.

It will be obvious that the falling curtain of liquid acceleratesdownwardly under the force of gravity, and the velocity of a givenincrement thereof increases with the distance from its origin. However,since the rate of flow of the liquid past any given level will beconstant, it will be seen that the cross sectional dimensions of thecurtain of liquid will be reduced as it falls. This may be seen inFIGURE 3 which shows how the curtain tends to draw in along its lengthto a shorter dimension. The width of the curtain will similarlydecrease.

However, as the velocity of the liquid increases, the effect of passinga filament through it will be lessened and, instead of being parted, thecurtain of liquid, at some level, will merely be diverted to one side ofthe filament. Accordingly, the filament must be passed through thecurtain of liquid at a level sufiiciently close to its source to causepartition.

It has been found that by thus passing a single filament through thecurtain of liquid, the latter is parted along a horizontal line and asubstantial horizontal space, free of liquid, is provided. It isbelieved that this takes place because the filament is sufiicient tomomentarily halt the liquid above it while the liquid therebeneathcontinues to accelerate while falling under the influence ofgravitational forces. The liquid above the filament is briefly haltedand thereafter recommences gravitational acceleration from a velocity ofzero at the level intercepted by the filament. However, the liquid belowthe wire has already achieved some velocity and continues to accelerateto even faster speeds, thereby increasing the distance between it andthe portion of liquid above the wire. The dimension of the space isaffected by the size of filament and the characteristics of the flowingliquid. Also, for a given filament the space will decrease withincreases in rate of flow of the liquid.

An apparatus devised for carrying out this method is shown in FIGURES 1through 3 wherein the various elements of apparatus are mounted upon asuperstructure, generally 10. A liquid coating applicator, or pouringdevice, generally 12, comprising a reservoir 14, having a sloped bottomwith an orifice opening 16, at the lowest point therein, produces asubstantially planar liquid curtain 18 which is received in a pan 20,spaced therebeneath. The liquid received in the pan 20 may berecirculated to the reservoir 14 by suitable apparatus, not shown.

An article to be coated by the liquid such as a side of leather 26 issupported upon a carrying member, generally 28. In the illustratedembodiment the carrying member comprises a frame 30, having a multitudeof lacings 32 by which the leather is tautly stretched within the frame.Each lacing 32 has a toggle fastener 34- at one end, secured to theleather, and is adjustably secured to the frame 30. The carrier frame 30is removably supported by a plurality of dogs 36 attached to a pair ofparallel spaced endless chains 38 trained beneath the reservoir 14.

At one side of the liquid reservoir 14, supported across the path of thecarrier frame 30, upon a pair of uprights, is a liquid curtaininterrupting means generally 40. The interrupter means comprises afilament 42, such as piano wire, tightly stretched between forward endsof a pair of parallel arms 44, 46. A tension rod 48 is connected betweenthe rear ends of arms 44, 46. The arms 44, 46 are held substantiallyperpendicular beyond the limits of the liquid curtain 18, and thefilament 42 is held horizontal and parallel to the curtain. Arms 44, 46are parts of four-bar linkages and are pivotally connected to a pair oflevers 50, 52 respectively, which are rotatably mounted on cantilevermembers 54, 56 extending from the superstructure uprights. A pair ofconnector links 58, 60 are pivotally connected to the ends of arms 44,46 and the cantilever members 54, 56. Thus, the arms 44, 46 will alwaysbe held parallel and horizontal while they arefree to be swungperpendicular to the liquid curtain 18.

Actuating means preferably comprising a pair of pneumatic cylinders, 62,64 are connected to the upper ends of levers 50, 52 by respective pistonrods 66, 68. The pneumatic cylinders in turn are secured to the upperends of the superstructure uprights. Actuation of the pneumaticcylinders to move the piston rods in either direction will result inreciprocation of the arms 44, 46 in the direction of the liquid curtain,passing the filament 42 through the latter.

A four-way valve, 72 (shown only in FIGURE 1) is connected by manifold74 to the forward ends of cylinders 6-2, 64, and by manifold 76 to therear ends thereof. The four-way valve 72 is actuated by a pair ofsolenoids 78, 80 to connect either manifold to a source of air underpressure (not shown) and the remaining manifold to atmosphere. Thesolenoids 78, 80 are connected across a source of electric power and atwo-way switch 82, which is operable to energize the solenoidsalternately so as to cause the four-way valve to connect first onemanifold and then the other to the source of air under pressure.

The two-way switch 82 is actuated in accordance with the position of thecarrying member generally 28 so as to pass the filament 42, through theliquid curtain 18 just prior to the time at which the exposed portion ofthe carrying member would intercept the curtain. The

switch 82 may obviously be actuated by various suitable means such asthe illustrated cam 84 which may be'driven either directly from thecarrying member power source, or by a time drive (neither shown). Thecam 84 is set to throw the switch 82 in accordance with the position ofthe dogs 36 on the endless chains 38. Also, it will be obvious that theswitch 82 could be replaced by suit+ able trip switches positioned inthe path of the carrying member, or by photoelectric cell. devices.

In operation, as the leading edge of the carrier frame 30 approaches thecurtain of liquid 18, the four-way valve 72 is actuated to deliver airunder pressure through manifolds 74 to the forward end of cylinders 62and 64. The piston rods 66, 68 are moved to the right (as shown inFIGURES 1 and 2) to swing levers 50, 52 clockwise and move the arms 44,46 to the left. The filament 42will be passed through the liquid curtain18, causing it to be briefly interrupted and parted as the carrier frame30 passes by. The liquid curtain 18 will almost immediately re-establishand fall continuously upon the leather 26.

As the rear portion of the frame 30 approaches the liquid curtain 18,the solenoid actuated valve 72 is reversed to deliver air under pressurethrough manifolds 76 to the rear end of cylinders 62, 64, reversing thepreviously described movements, and moving the filament 42 again throughthe liquid curtain from left to right. The currain will again be brieflyinterrupted and parted as exposed following edge of the carrier framepasses through.

The carrier frames 30 may be mechanically or manually placed upon theendless chains 38 to the left of the coating apparatus and similarlyremoved after passing therebeneath. Frames are then stacked or otherwisehandled while the coated leather dries.

The operations will be continuously repeated as subsequent carrierframes transport articles through the liquid curtain 18. Also, it willbe obvious that a single carrying member may be reciprocated betweenpositions to either side of the coating apparatus and the device willperform equally well. Also, it will be obvious that a single actuatingmeans could be used in place of the pair of pneumatic cylindersillustrated.

An apparatus for coating leather with solvent type patent leather.finish has been constructed and operated in accordance with theforegoing description. In that apparatus a reservoir containing a 6 to 8inch head of liquid capable of delivering a curtain 50 to 109 incheslong (according to the width of leather) at the rate of 10 to 20 g.p.m.is spaced with the orifice 6 inches above the path of a carrier frame.The filament member is located to pass through the curtain 1 inch belowthe orifice. In this instance the filament was No. 20 piano wire. Thefilament is actuated by a cam mechanism to intercept the liquid curtainjust prior to the leading edge and trailing edge of the frame reachingthe curtain. A 4 to 5 inch space is produced in the curtain allowing a 1/2 inch diameter frame to pass through uncoated at a speed of 3.75ft./sec. With this apparatus it is possible to coat approximately 400hides of leather per hour (constituting approximately 16,000 sq. ft.),allowing one pass per hide through the liquid curtain. Frames with hidesare stacked, after coating, while the coating is dried and cured; andsubsequently again passed through the coating apparatus one or moreadditional times until the desired finish is built up. No irregularityor unevenness in the applied coating has been observed.

Obviously, many other modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and, therefore, only such limitations should be imposedas areindicated in the appended claims.

I claim:

1. An improved method for coating flexible articles by pouring a curtainof liquid material thereon, said method comprising: placing each articleon a frame member having an exposed leading edge; moving the frame andarticle on a given path; continuously pouring a curtain of liquidmaterial across said path; and reciproeating a single filament throughsaid curtain of liquid in timed relation to the movement of said frameand said article and at a level above said frame selected to brieflyinterrupt said curtain as said exposed leading edge of said frame passestherebeneath, said filament being held horizontal and parallel to saidcurtain of liquid.

2. An improved apparatus for coating a surface of an item with a liquidmaterial, said apparatus comprising, in combination: conveyor means forsupporting and carrying the item to be coated in a given path; pouringmeans disposed above the path of said conveyor means for delivering acurtain of liquid material through which the item will pass; moveablefilament means to briefly interrupt the curtain of liquid material, saidfilament means being positioned between said conveyor means and saidpouring means, and actuating means connected to reciprocate saidmoveable filament means through said curtain of liquid in timed relationto said conveyor means.

3. An improved apparatus for coating the surface of an item with aliquid material, said apparatus comprising, in combination: areciprocable conveyor frame for supporting the item to be coated, saidconveyor frame mov ing in a given path and having an exposed leadingedge disposed transversely to said path; pouring means posltioned abovethe path of said conveyor frame for continuously delivering a curtain ofliquid material substantially transverse to said path through which theitem will be passed; a filament tautly held parallel to said curtain ofliquid material between said coating means and said path; and actuatingmeans connected to reciprocate said filament through said curtain ofsaid liquid material proximate to said coating means to brieflyinterrupt said curtain just prior to the exposed leading edge of saidconveyor frame reaching said curtain, whereby said leading edge willpass beneath said pouring means free of said liquid material.

4. In combination with apparatus for pouring a con tinuously descending,substantially planar, curtain of liquid material upon articles to becoated therebeneath, an improvement for interrupting said curtain ofliquid, said improvement comprising: a single filament held parallel tothe plane of said curtain of liquid; and reciprocating means supportingsaid filament to move it perpendicular to said plane and through saidcurtain of liquid.

5. In combination with apparatus for pouring a continuously descending,substantially planar, curtain of liquid material upon articles to becoated therebeneath, an improvement for interrupting said curtain ofllquid, said improvement comprising: a pair of spaced parallel armspositioned perpendicular to said curtain of liquid; a length of wirestretched between ends of said arms, said wire being parallel to, and ata level closely below, the origin of said curtain; and means toreciprocate said arms toward said curtain to pass said length of Wireconcurrently through the length of said curtain whereby said liquidmaterial will be interrupted through its length.

References Cited by the Examiner UNITED STATES PATENTS 813,857 2/ 1906Carter 118-25 1,940,269 12/1933 Pierce 1182 1,966,093 7/1934 Griffin1182 2,069,845 2/ 1937 Paasche 118326 2,716,622 8/1955 Foster 118-93,102,046 8/1963 Bushey 118-301 JOSEPH B. SPENCER, Primary Examiner.

RICHARD D. NEVIUS, Examiner.

1. AN IMPRIVED METHOD FOR COATING FLEXIBLE ARTICLES BY POURING A CURTAIN OF LIQUID MATERIAL THEREON, SAID METHOD COMPRISING: PLACING EACH ARTICLE ON A FRAME MEMBER HAVING AN EXPOSED LEADING EDGE; MOVING THE FRAME AND ARTICLE ON A GIVEN PATH; CONTINUOUSLY POURING A CURTAIN OF LIQUID MATERIAL ACROSS SAID PATH; AND RECIPROCATING A SINGLE FILAMENT THROUGH SAID CURTAIN OF LIQUID IN TIMED RELATION TO THE MOVEMENT OF SAID FRAME AND SAID ARTICLE AND AT A LEVEL ABOVE SAID FRAME SELECTED TO BRIEFLY INTERRUPT SAID CURTAIN AS SAID EXPOSED LEADING EDGE OF SAID FRAME PASSES THEREBENEATH, SAID FILAMENT BEING HELD HORIZONTAL AND PARALLEL TO SAID CURTAIN OF LIQUID. 